I am currently rebuilding my engine for a compound boost set up. I made this decision after damaging my supercharger by running meth and nitrous!!!!! :facepalm:Huge no-no. The water froze and pretty much acted like stones in the supercharger, deep scratches and funny noises followed.:thumbdwn:

So in my quest for more go fast I decided to rebuild something insane, so here we go...:thumbsup::woot:

I am ordering a T72 turbo for a rear mount set up. I will be running 8 psi on th SC and 9 psi on the turbo. My concern is the tuning and any equipment that would make my life easier.

PLEASE UNDERSTAND...I am looking for positive feed back of known issues and experiences, or known related issues of the build. I say that to say I'm not interested in how stupid the build is....thanks. All comments are appreciated.

lab rat

10-31-2011 12:33 AM

Don't quite see the benefit of the turbo with the SC setup, why not just turn the boost up on the SC?

Commanderwiggin

10-31-2011 12:41 AM

Looking forward to results :P

02PRUV

10-31-2011 01:16 AM

Haven't tried compound charging on anything before but compound turbocharging is very interesting and I want to try it on something one day.

Interested to see the results as well

Bdave

10-31-2011 01:20 AM

I think your injectors are too small. 1000 or even 1200cc.
Fuel pump is too small to supply all that FI too.need BIGGER!
You should try and find an old fuel rail kicking around...one from a Stage THREE HPF kit. You got AIR. Now you need FUEL....and lots of it by the look.

PEI330Ci

10-31-2011 07:34 AM

Unless you plan on running a direct port setup right behind the fuel injector bungs on the port runner, I wouldn't run nitrous.

How do you plan to tune this monster?

PEI330Ci

10-31-2011 07:35 AM

Unless you plan on running a direct port setup right behind the fuel injector bungs on the port runner, I wouldn't run nitrous.

How do you plan to tune this monster?

bluejeansonfire

10-31-2011 08:31 AM

why rear-mount?

bluejeansonfire

10-31-2011 08:33 AM

Quote:

Originally Posted by diablorojo
(Post 13752033)

I am ordering a T72 turbo for a rear mount set up. I will be running 8 psi on th SC and 9 psi on the turbo. My concern is the tuning and any equipment that would make my life easier.

do you know how much boost a 8psi pulley and 9psi wastegate spring yield?

diablorojo

10-31-2011 08:42 AM

I can't turn up boost on the turbo because of the compound effect, 8psi on SC and 9psi on turbo gives the car 23psi. Thats why im using a large turbo 9psi on a 700+ turbo should do well. I want to get it running right. Once I do I will look at lowering compression lower and turning up boost.

I'm going rear mount on the turbo to keep the heat down under the hood and rear mount allows turbo boost without an intercooler. Less piping, and general ease. It also allows for a simple setup in the event this doesn't work.

Fuel....I considered larger but I figured running 32lb injectors on 13psi of boost (currently) so doubling the boost would be 65lbs, but I actually am going to see if I can squeeze enough room in them to go e85. I'll know after the first tune...

E46_330i_Stud

10-31-2011 08:50 AM

Wow in for results. Should be a MONSTER. :bow:

bluejeansonfire

10-31-2011 08:51 AM

given that the inlet of the supercharger will be seeing 9psi, and will then be ratcheting that well past 20psi... do you think that narrow belt will hold to redline?

you intend to run 23+psi on a hg spacer?

PEI330Ci

10-31-2011 09:05 AM

How is this being tuned?

This should be the first item looked at in any custom build on an E46.

BDUB328I

10-31-2011 09:44 AM

this sound like a very interesting setup, im excited to see some results

B33MER

10-31-2011 10:13 AM

Can someone explain to me what is compound boost? Sorry am still a noob in FI :(

Estoril-E46

10-31-2011 10:29 AM

Quote:

Originally Posted by diablorojo
(Post 13752626)

I can't turn up boost on the turbo because of the compound effect, 8psi on SC and 9psi on turbo gives the car 23psi. Thats why im using a large turbo 9psi on a 700+ turbo should do well. I want to get it running right. Once I do I will look at lowering compression lower and turning up boost.

I'm going rear mount on the turbo to keep the heat down under the hood and rear mount allows turbo boost without an intercooler. Less piping, and general ease. It also allows for a simple setup in the event this doesn't work.

Fuel....I considered larger but I figured running 32lb injectors on 13psi of boost (currently) so doubling the boost would be 65lbs, but I actually am going to see if I can squeeze enough room in them to go e85. I'll know after the first tune...

Gut tells me you are going to see more boost then that. Just because it initially compresses to that, doesn't mean your engine is going to suck it in that fast. It will probably build up the way it does for a PD blower.

lab rat

10-31-2011 11:03 AM

All great inventors were considered fools at some point.
I just see this being too complicated. How much power are you trying to make? Stock internals with head spacer will likely stop you well before 400whp.

E46_330i_Stud

10-31-2011 11:16 AM

Quote:

Originally Posted by lab rat
(Post 13752904)

All great inventors were considered fools at some point.
I just see this being too complicated. How much power are you trying to make? Stock internals with head spacer will likely stop you well before 400whp.

Technique Tunings kit with a thicker head gasket and studs puts down 400whp on like 11psi. Might be a little more boost. OP just needs to be careful not to lift the head enough to strip the head studs straight out of the aluminum block. But I agree, the internals will need work for sure.